It is required to measure the true open circuit e.m.f. of a battery. The best device is_____________?

Related Mcqs:

1. The spring material used in a spring control device should have the following property?

   A. Should be non-magnetic
   B. Most be of low temperature co-efficient
   C. Should have low specific resistance
   D. Should not be subjected to fatigue
   E. All of the above

2. A __________ device prevents the oscillation of the moving system and enables the latter to reach its final position quickly___________?

   A. deflecting
   B. controlling
   C. damping
   D. any of the above

3. Basically a potentiometer is a device for________________?

   A. comparing two voltages
   B. measuring a current
   C. comparing two currents
   D. measuring a voltage
   E. none of the above

4. Wagner earthing device is used to eliminate errors due to________________?

   A. electrostatic coupling
   B. electromagnetic coupling
   C. both A. and B.
   D. none of the above

5. is an instrument which measures the insulation resistance of an electric circuit relative to earth and one another_______________?

   A. Tangent galvanometer
   B. Meggar
   C. Current transformer
   D. None of the above

6. The resistance in the circuit of the moving coil of a dynamometer wattmeter should be_____________?

   A. almost zero
   B. low
   C. high
   D. none of the above

7. The power of a n-phase circuit can be measured by using a minimum of_______________?

   A. (n – 1) wattmeter elements
   B. n wattmeter elements
   C. (n + 1) wattmeter elements
   D. 2n wattmeter elements

8. Induction type single phase energy meters measure electric energy in_______________?

   A. kW
   B. Wh
   C. kWh
   D. VAR
   E. None of the above

9. To measure a resistance with the help of a potentiometer it is_________________?

   A. necessary to standardise the potentiometer
   B. not necessary to standardise the potentiometer
   C. necessary to use a volt ratio box in conjunction with the potentiometer
   D. none of the above

10. To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supply for the potentiometer in taken_______________?

    A. from a source which is not the same as the unknown voltage
    B. from a battery
    C. from the same source as the unknown voltage
    D. any of the above